Remote-controlled grapple

ABSTRACT

A pair of pivoted grapple hooks extend downward from a turntable mounted on a housing supported for movement between working sites. The turntable is driven by a hydraulic motor in the housing. One end of a cable is connected to the hooks and extends upward through a central opening in the turntable, thence over a pulley on the end of an extensible hydraulic piston-cylinder unit in the housing, and its opposite end is secured to the housing. Extension and retraction of the piston-cylinder unit effects opening and closing of the hooks. An electric motor in the housing receives power from a battery source in the housing to drive a hydraulic pump which supplies hydraulic pressure to the hydraulic motor and piston-cylinder unit through sequential operation of solenoid valves controlled by an electronic control circuit which, in turn, is activated by operation of a radio frequency receiver in the housing from a remotely transmitted radio frequency signal.

United States Patent Hale et a1. Mar. 7, 1972 [54] REMOTE-CONTROLLED GRAPPLE Primary Examiner-Harvey C. Homsby [72] Inventors: Gordon H. Hale, 13055 McKenzie Hwy.; j i 'g'"'.

James M. Fay, 890 O St., both of Spring- "0mey e15 er field, Oreg. 97477 I ABSTRACT [22] Nov. 1969 A pair of pivoted grapple hooks extend downward from a PP 6,740 turntable mounted on a housing supported for movement between working sites The turntable is driven by a hydraulic [521 us. (:1 .I ..294/111, 212/84, 212/89, motor in the housingone end of a Cable is Connected to the 212/127 212/129 hooks and extends upward through a central opening in the [51] lnt.Cl ..B66c 1/00 turntable thence over P y end of an extensible 158] Field of Search ..294/111, 112; 212/81, 84, 89, hydraulic Piston-cylinder unit in the housing. and its pp 212/127, 129 end is secured to the housing. Extension and retraction of the piston-cylinder unit effects opening and closing of the hooks. [56] References Cited An electric motor in the housing receives power from a battery source in the housing to drive a hydraulic pump which UNITED STATES PATENTS supplies hydraulic pressure to the hydraulic motor and piston- 3,401,974 9/1968 Martelee ..294/110 Cylinder unit through sequential operation of solenoid valves 3 540 770 11 /197 i ll 294/106 X controlled by an electronic control circuit which, in turn, is 1 439 549 12/1922 11 294/1 11 activated by operation of a radio frequency receiver in the 2 9945 54 8/1961 Harryfl 294/1 1 1 housing from a remotely transmitted radio frequency signal. 3,359,033 12/1967 Curtis ....294/l1 X 3,407,942 10/1 968 McIntyre et a1 ..212/81 x 6 Chums 5 Drawmg Figures FOREIGN PATENTS OR APPLICATIONS 273,437 11/1912 Germany ..212/81 PATENTEDMAR 7:912 3.647, 255

" s I h.

JAMES M. FAY

INVENTORS.

GORDON H. HALE Pmimmm "1 I912 3, e47. 255

SHEET 2 BF 2 8O 73 76 7 I04 FIG 5 M 40 M 52 86 92 88 GORDON H. HALE JAMES M. FAY

INVE NTORS.

ATTY.

REMOTE-CONTROLLED GRAPPLE BACKGROUND OF THE INVENTION This invention relates to grapples, and more particularly to a grapple in which operation of the hooks is controlled from the safety of a remote position.

Grapples have been employed heretofore for a variety of purposes, including recent use in hauling logs from a cutting site to a collection site. The latter use has effectively reduced the number of workmen required for the purpose, as compared with logging by chokers. However, the construction of such grapples has imposed significant operating limitations and hazards. For example, such grapples are opened and closed either by manual operation of a line at the grapple, or by mechanical operation of a line extending from the grapple to the collection site. Manual operation requires an operator to be in close proximity to the grapple, and thus presents the hazard of injury to personnel. Mechanical operation requires more costly equipment and is slower and less reliable in operation because of the problems of communication between the operator at the grapple and the operator at the collection site. Both types of operation require manual manipulation of the grapple by an operator in order to rotate the hooks into proper positionfor engaging a log. The operator thus is subject to excessive physical exertion and to the hazard of injury, and the grapple is subject to possible jamming or other malfunction caused by the twisting of operating lines.

SUMMARY OF THE INVENTION In its basic concept this invention provides a grapple in which the hooks are opened, closed and rotated by means of a self-contained drive and control assembly operated from the safety of a remote position.

It is by virtue of the foregoing basic concept that the principal object of this invention is achieved; namely, to overcome the disadvantages and limitations of prior grapple systems, as enumerated hereinbefore.

Another important object of this invention is the provision of a grapple of the class described in which operation of the hooks is effected by transmission of a single radio frequency signal from a remote position.

A further important object of this invention is the provision of a grapple of the class described which is of simplified and rugged construction for economical manufacture and long and faithful operation with a minimum of maintenance and repair.

The foregoing and other objectives and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevation of a logging system incorporating a grapple embodying the features of this invention, .the grapple hooks being shown open in full lines and closed in broken lines.

FIG. 2 is a fragmentary view in side elevation of the housing component of the grapple, parts being broken away to disclose details of internal construction.

FIG. 3 is a fragmentary plan view as viewed from the top in FIG. 2, the top of the housing being broken away to disclose details of internal construction.

FIG. 4 is a schematic diagram of electrical control circuitry for operating the grapple of the preceding views.

FIG. 5 is a schematic diagram of a hydraulic drive system for the grapple.

DESCRIPTION OF THE PREFERRED EMBODIMENT The grapple of this invention includes a plurality of grapple hooks which extend downward from a housing 12 support for movement between'spaced working stations. In FIG. 1 the grapple is illustrated in a log-hauling system wherein the housing is suspended from chains 14 connected to rollers 16 which track on the haul-back cable 18. As is well known, the haulback cable extends from a haul-back winch drum at a yarder boom, thence through a tail block located at the log cutting site and then back to the housing 12 where its free end is anchored. The main, or inhaul cable 20 is anchored at the opposite end of the housing and extends therefrom to a main winch drum at the yarder boom. Thus, the housing may be moved toward the yearder boom by drawing in on the main cable, and may be moved toward the tail block by drawing in on the haul-back cable.

It will be apparent that the grapple housing may be supported for movement in any of a variety of ways. For example, when used in logging the rollers 16 may track on separate slackline, rather than upon the haul-back cable as illustrated. For other uses, the grapple housing may be suspended from a cable extending from a crane boom or other support.

In the embodiment illustrated the grapple includes a pair of grapple hooks 10 which are connected together pivotally intermediate their ends by means of a pivot shaft 22. The ends of the hooks opposite the gripping ends are connected pivotally through links 24 to spaced anchor lugs 26 projecting downward from the housing 12. In the preferred embodiment illustrated, which provides means for rotating the hooks, these lugs are anchored to a turntable 28 which is supported by the housing for axial rotation relative to the latter.

The turntable includes a central hub 30 (FIG. 2) which extends freely through an annular bearing 32 secured in a central opening in the bottom wall of the housing. Secured to the hub, as by welding, and contained within the housing is an annular backing plate 34 which rests on the bearing. Formed integral with, or otherwise secured to the annular plate is a gear 36. This gear meshes with a gear 38 secured to the output shaft of a rotary hydraulic motor 40 mounted within the housing. Thus, upon the application of hydraulic pressure to the motor, as described hereinafter, the turntable is caused to rotate.

Drive means is provided for opening and closing the grapple hooks. In the embodiment illustrated, the turntable and associated hub are provided with a central opening 42 which freely receives therethrough a length of cable 44. The end of the cable extending downward through the opening is attached to a swivel 46 (FIG. I) carried on the upper end of an anchor plate 48. This plate is interposed between the grapple hooks l0 and is provided with an opening which receives the pivot shaft 22 through it.

The cable extends into the housing through the central opening in the turntable and is trained over a pulley 50 (F IG.

2) mounted rotatably in the housing on a shaft 52. The cable then is trained about a pulley 54 mounted on a shaft 56 carried by the supporting yoke 58 secured to the projecting end of an elongated piston rod 60 of an extensible piston-cylinder unit. The piston rod extends into a hydraulic cylinder 62 and is there attached to a piston 64 which is reciprocative within the cylinder. The cylinder is mounted within the housing by such means as the pivot pin 66 and bracket 68. The end of the cable within the housing is anchored to the latter by means of the anchor pin 70 which extends though the cable coupling 72 and lug 74 projecting inwardly from the sidewall of the housing.

Thus, upon the application of hydraulic pressure to the opposite ends of the cylinder to effect extension and retraction of the piston rod, the grapple hooks are caused to open and close, respectively. Extension of the cable 44 freely through the central opening 42 in the turntable and connection of the outer end of the cable to the pivot shaft 22 of the hooks through the swivel 46, allows the hooks to rotate with the turntable without twisting or otherwise adversely affecting the cable.

Referring now particularly to FIG. 5 of the drawings, there is illustrated schematically a hydraulic system for supplying hydraulic pressure selectively to the hydraulic motor 40 and to the cylinder 62 of the piston-cylinder unit. An electric motor 76 within the housing has its output shaft coupled to a hydraulic pump 78 also contained within the housing. The pressure outlet of the pump is connected through the conduits 80 to inlet ports of solenoid valves 82 and 84, and the return inlet of the pump is connected through the conduits 86 to exhaust ports of the valves.

When solenoid 88 associated with the valve 82 is energized, the valve is moved to communicate hydraulic pressure in the conduit 80 with conduit 90 leading to the inlet of the hydraulic motor 40 and to communicate exhaust conduit 92 of the motor with the return conduit 86 to the pump 78. The hydraulic motor thus is activated to rotate the turntable. When the solenoid is deenergized, the valve is returned to its normally open center position to deactivate the hydraulic motor.

When solenoid 94 associated with the valve 84 is energized, the valve is moved to communicate the hydraulic pressure conduit 80 with conduit 96 communicating with the end of the cylinder 62 opposite the piston rod 60 and to communicate conduit 98 at the opposite end of the cylinder with the return conduit 86 to the pump. The piston rod thus is caused to extend from the cylinder to effect opening of the grapple hooks 10. The, limit of extension of the piston rod, and hence the limit of opening of the hooks, is controlled by an electric switch 100 (FIGS. 2 and 4). The actuator of this switch is engaged by an arm 102 extending laterally from the piston rod. As explained more fully hereinafter, opening of this switch effects deactivation of solenoid 94, whereupon the valve returns to its normally closed position.

Upon activation of solenoid 104 associated with the valve 84, the latter is moved to communicate the conduit 96 with the return conduit 86 to the pump 78. Since the electric motor 76 is not energized during the hook closing cycle, no hydraulic pressure is supplied to the cylinder 62. The piston rod thus is caused to retract into the cylinder to effect closing of the grapple hooks by the force of gravity acting upon the massive structure of the hooks. The limit of retraction of the piston rod is controlled by a switch 106. When the actuator of this switch is engaged by the arm 102 the switch opens to deactivate solenoid 104 and return the valve 84 to its normally closed position, as explained more fully hereinafter.

Means is provided for controlling the operation of the electric motor 76 and solenoid valves 82, 84 from the safety of a remote position. This means is provided, in the embodiment illustrated in FIG. 4, by an electrical control system the source of electric potential for which is provided by batteries contained removably in compartments 108 and 110 provided in the housing. These batteries also provide electric potential for the electric drive motor and the solenoid valves, as will appear hereinafter. The top of the housing is removable for access to the batteries and other components, as will be understood.

Operation of the control circuit is controlled by an electric switch 112 which is operated by a radio frequency receiver 114 carried in a compartment 116 in the housing. The receiver is activated by a transmitter located at a remote position and providing an output signal of the same frequency as the receiver. For example, when the grapple is being used in logging, the signal is provided by portable transmitters, one carried by an operator in the cutting area and the other carried by an operator at the collection site.

The control circuit illustrated in FIG. 4 is best described in conjunction with the operation of the grapple, as follows: Let it be assumed that the grapple hooks are fully opened, as illustrated in full lines in FIG. 1, and positioned over a log L to be conveyed to a. collection site. In this position of the hooks the hook-opening limit switch 100 is transferred to the position illustrated in FIG. 4 and the hook-closing limit switch 106 is closed. As described more fully hereinafter, this condition was established by conduction of transistor 120 of bistable multivibrator 122, after which the multivibrator transferred to conduction of the other transistor 124, as will be understood.

To retract the piston rod 60 and close the hooks upon the log, the operator at the cutting site keys the transmitter to radiate a radio frequency signal to the receiver 114. Activation of the receiver results in closure of the control switch 1 12 and consequent transfer of the multivibrator from conduction of transistor 120 to conduction of transistor 124. Transistor 126 thus is caused to conduct, completing the electric circuit of relay 128 through the closed retract limit switch 106. The contact of relay 128 closes to complete the electric circuit of the solenoid 104 of the valve 84 which effects retraction of the piston rod and closure of the grapple hooks, as previously explained. Upon release of the transmitter key the relay 128 and solenoid 104 remain activated, thus maintaining the hooks closed on the log. if the log is so small that the piston rod reaches its limit of retraction, the retraction limit switch 106 opens, thereby deenergizing the valve solenoid 104 and returning the valve to its closed position.

The operator at the cutting site then signals the operator at the yarder boom to elevate the grapple and attached log and haul the latter in to the collection site.

When the log arrives at the collection site the operator at that position keys his transmitter to activate the receiver 114. The resulting closure of the control switch 112 now transfers conduction to multivibrator transistor 120 which, in turn, ef' fects conduction of transistor 130. Conduction of this transistor completes the electric circuit of the relay I32 through the extension limit switch which has transferred from the position illustrated in FIG. 4 as a result of closing of the grapple hooks. Activation of relay 132 effects closure of its associated contacts A and B. Closure of contact A completes the electric circuit of the relay 134 the contact of which thereupon closes to activate the electric motor 76. C losure of the other contact B completes the electric circuit of the coil 94 of the solenoid valve 84 to effect extension of the piston rod 60 and consequent opening of the grapple hooks 10 to release the log. The operator at the yarder then returns the grapple to the logging site.

Let it now be assumed that the operator at the cutting site desires to rotate the hooks 10 in order to align them properly with a log. Since the hooks are fully open, the extension limit switch 100 is again moved to the position illustrated in FIG. 4. However, since the next keying of the transmitter to activate the receiver 114 and close the control switch [12 will function to energize the relay 128 to effect closure of the hooks, this keying by the operator at the cuttingsite is made as short as possible to minimize the degree of closing of the hooks. The operator then keys the transmitter a second time, holding the key closed. The multivibrator 122 thereupon transfers conduction to transistor 120, energizing relay 132 to effect full opening of the hooks. With the transmitter key still closed, an electric circuit is completed through the closed control switch 112 and the extension limit switch 100, as positioned in FIG. 4, to cut off normally conducting transistor 136. This transistor functions when conducting to short a time delay capacitor 138. However, when the transistor is cut off the capacitor is caused to charge at a rate determined by the RC constant of the capacitor and its associated resistor 140. Upon charging of the capacitor, after a time delay of for example 3 seconds, silicon-controlled relay 142 is caused to conduct and activate transistor 144. Conduction of this transistor completes the electric circuit of relay coil 146 to close its associated contacts A and 8. Closure of contact B completes an electric circuit for the relay 134, causing its associated contact to close and activate the electric drive motor 76. Closure of the other relay contact A completes the electric circuit of the solenoid 88 of the valve 82, whereupon the latter moves to supply hydraulic pressure to the hydraulic motor 40 to effect rotation of the turntable 28. When the hooks 10 have been rotated to the desired position, the operator releases the transmitter key to open the control switch 112 and deactivate the delay circuit and valve solenoid 88.

Having thus oriented the open grapple hooks properly with respect to the log, the operator again keys the transmitter to effect closure of the hooks, as previously explained.

Fromthe foregoing it will be apparent that control of the opening, closing and rotation of the grapple hooks is provided by the use of a single radio frequency signal available to the operator at the cutting site and also to the operator at the yarder. This arrangement materially simplifies the control system and correspondingly minimizes the cost of the grapple. The arrangement further simplifies the operation of the grapple and contributes materially to maximum logging production at minimum cost.

It will be apparent to those skilled in the art that various changes may be made in the size, shape, number, type and arrangement of parts described hereinbefore without departing from the spirit of this invention.

Having now described our invention and the manner in which it may be used, we claim:

1. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites,

b. a turntable mounted on the housing and having a central opening therethrough,

c. a pair of hooks extending downward from the turntable for rotation with the latter and for movement between open and closed positions,

d. a flexible hook-operating cable in the housing having an end portion extending downward freely through the central opening in the turntable,

e. a swivel below the turntable connecting said downwardly extending end of the cable to the hooks, with the rotational axis of the swivel aligned with said portion of the cable.

f. means engaging the turntable enabling said turntable to be rotated independently of said cable and housing,

g. hook drive means in the housing engaging the cable for moving the swivel-connected end vertically toward and away from the turntable for opening and closing the hooks, and

h. hook drive control means connected to the hook drive means for operating the latter.

2. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites,

b. turntable means mounted on the housing and having a central opening therethrough,

c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions,

d. flexible hook-operating cable means,

e. swivel means connecting one end of the cable means to the hooks,

f. the cable means extending upward freely through the opening in the turntable means into the housing,

g. hook drive means in the housing engaging the cable means for moving the swivel-connected end vertically for opening and closing the hooks,

h. hook drive control means connected to the hook drive means for operating the latter,

i. turntable drive means in the housing engaging the turntable means for rotating the latter independently of the cable means,

j. electric turntable drive control means connected to the turntable drive means for operating the latter, and

k. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to actuate the turntable drive means for rotating the turntable means.

3. The grapple of claim 2 including time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the books.

4. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites,

b. turntable means mounted on the housing.

c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions, d. cable means secured at one end to the hooks and extendj. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to actuate the turntable drive means for rotating the turntable means.

5. The grapple of claim 4 including time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the hooks.

6. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites,

b. turntable means mounted on the housing and having in central opening therethrough,

c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions,

d. cable means secured at one end to the hooks and extending upward therefrom freely through the turntable opening into the housing,

e. hook drive means in the housing engaging the cable means for moving said one end vertically for opening and closing the hooks, the hook drive means comprising 1. an extensible hydraulic piston-cylinder unit,

2. a hydraulic pump,

3. an electric motor connected to the pump for driving the latter, and

4. electrically operated valve means interconnecting the pump and piston-cylinder unit for extending and retracting the latter,

. electric hook drive control means in the housing connected to the electric motor and valve means and including 1. an electric circuit including a battery source of electric potential,

2. switch means in the electric circuit, and

3. radio frequency responsive switch actuator means in the housing for actuating the switch means upon response to a radio frequency signal transmitted from a position remote from the housing,

g. turntable drive means in the housing engaging the turntable means for rotating the latter, the turntable drive means comprising 1. a hydraulic motor, and 2. electrically operated valve means interconnecting the pump and hydraulic motor.

h. electric turntable drive control means connected to the hydraulic motor valve means and including an electric circuit including said switch means,

i. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to activate said circuit for rotating the turntable means, and

j. time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the hooks. 

1. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites, b. a turntable mounted on the housing and having a central opening therethrough, c. a pair of hooks extending downward from the turntable for rotation with the latter and for movement between open and closed positions, d. a flexible hook-operating cable in the housing having an end portion extending downward freely through the central opening in the turntable, e. a swivel below the turntable connecting said downwardly extending end of the cable to the hooks, with the rotational axis of the swivel aligned with said portion of the cable. f. means engaging the turntable enabling said turntable to be rotated independently of said cable and housing, g. hook drive means in the housing engaging the cable for moving the swivel-connected end vertically toward and away from the turntable for opening and closing the hooks, and h. hook drive control means connected to the hooK drive means for operating the latter.
 2. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites, b. turntable means mounted on the housing and having a central opening therethrough, c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions, d. flexible hook-operating cable means, e. swivel means connecting one end of the cable means to the hooks, f. the cable means extending upward freely through the opening in the turntable means into the housing, g. hook drive means in the housing engaging the cable means for moving the swivel-connected end vertically for opening and closing the hooks, h. hook drive control means connected to the hook drive means for operating the latter, i. turntable drive means in the housing engaging the turntable means for rotating the latter independently of the cable means, j. electric turntable drive control means connected to the turntable drive means for operating the latter, and k. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to actuate the turntable drive means for rotating the turntable means.
 2. a hydraulic pump,
 2. switch means in the electric circuit, and
 2. electrically operated valve means interconnecting the pump and hydraulic motor. h. electric turntable drive control means connected to the hydraulic motor valve means and including an electric circuit including said switch means, i. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to activate said circuit for rotating the turntable means, and j. time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the hooks.
 3. radio frequency responsive switch actuator means in the housing for actuating the switch means upon response to a radio frequency signal transmitted from a position remote from the housing, g. turntable drive means in the housing engaging the turntable means for rotating the latter, the turntable drive means comprising
 3. an electric motor connected to the pump for driving the latter, and
 3. The grapple of claim 2 including time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the hooks.
 4. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites, b. turntable means mounted on the housing. c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions, d. cable means secured at one end to the hooks and extending upward therefrom into the housing, e. hook drive means in the housing engaging the cable means for moving said one end vertically for opening and closing the hooks, f. electric hook drive control means connected to the hook drive means for operating the latter, g. a hydraulic turntable drive motor in the housing engaging the turntable means for rotating the latter, h. electrically operated valve means connected to the hydraulic motor, i. electric turntable drive control means connected to the valve means for operating the latter, and j. switch means in the electric circuit of the turntable drive control means operable upon opening of the hooks to actuate the turntable drive means for rotating the turntable means.
 4. electrically operated valve means interconnecting the pump and piston-cylinder unit for extending and retracting the latter, f. electric hook drive control means in the housing connected to the electric motor and valve means and including
 5. The grapple of claim 4 including time delay means in the electric circuit of the turntable drive control means for delaying operation of the turntable drive means for a period of time following opening of the hooks.
 6. A grapple comprising a. a housing adapted to be supported for movement between loading and unloading sites, b. turntable means mounted on the housing and having a central opening therethrough, c. a pair of hooks extending downward from the turntable means for rotation with the latter and for movement between open and closed positions, d. cable means secured at one end to the hooks and extending upward therefrom freely through the turntable opening into the housing, e. hook drive means in the housing engaging the cable means for moving said one end vertically for opening and closing the hooks, the hook drive means comprising 